8 Responses. > 1  the Moon takes an elliptical path around the Earth. The planets make nearly elliptical orbits around the Sun, close enough for reasonable approximations, but the Moonâs Orbit around the Earth is sufficiently influenced by the Sun that it follows a path detectably different from an ellipse.
Quick Answer. In 1896, French scientist Antoine Henri Becquerel discovered radioactivity which was an early contribution to atomic theory. He discovered this phenomenon while experimenting with uranium and a photographic plate. Continue Reading.
In 1896 Henri Becquerel discovered a new phenomenon that Curie would soon name radioactivity, and together with Pierre she discovered two new elements, polonium and radium, in 1898. For their discovery of radioactivity, the three won the 1903 Nobel Prize for physics.